Process of producing a two-toned finish on metal surfaces



Patented Nov. 4, 1930 UNITED STATES PATENT OFFICE MARVIN J. UDY, F NIAGARA FALLS, NEW YORK No Drawing.

The invention is a process of producing a two-toned finish on the surface of metal articles in a single electroplating operation.

In accordance with my invention I may prepare the article for the finishing process by giving its surface a high gloss or luster by submitting it to one of the well known burnishing operations such as polishing or buffing, or it may be engrailed, pebbled, corrw in gated, pitted, knurled, or otherwise givena rough or uneven surface, or it may be left in its original condition, although I prefer to apply my process to articles having a polished surface.

After the surface of the article hasbeen prepared for the finishing processa portion of it is then covered with a viscous substance.

or medium which has a retarding effect upon the electroplating operation which follows and will be described presently. The substance forming the retarding covering or coating may comprise many of the coating materials such as paint, enamel, ink, and the like, but I prefer to employ what is known as rc-etching ink which will be referred to hereinafter simply as ink.

The ink may be traced upon the surface of the article to form a descriptive or ornamental design or it may be applied by other Well 3 known means such as a brush or spray, al-.

though I prefer to apply it through the openings in a rubber stencil as I have found this a quick and accurate method of forming the design coating. i The article with its partially coated surface is then immersed in an electroplating solution or bath and subjected to electroplating or electrodepositing action until both the coated and uncoated portions of its surface are plated, with an electrodeposit. Preferably, I employ a chromic acid chromium plating solution, containing a small amount of a sulphate-containing compound, or a compound containing an equivalent radical, such solutions being now well known, although others may be used. During the plating op eration the ink retards the chromium deposition until the portion of the surface of the article covered by the ink has become etched by Application filed July 28,

1927. Serial No. 209,176.

the action of the plating solution. Also, during the plating operation, the inkis oxidized by the action of the plating solution and gradually removed from the surface of the article thereby permitting chromium to be deposited upon that portion of the surface of the article formerly covered by the ink. The portion of the surface of the article not covered by the ink is plated, during the plating operation, in the usual manner.

The chromium plating deposited upon the article during the plating operation has an outer surface of substantially the same character as the surface upon which it is deposit ed. Therefore, the character of that portion of the surface of the article not covered by the ink is substantially the same after it is plated as it was before. But, that portion of the surface of the article covered by the ink is so rpughened during the process by the 7 etching action of the plating solution that the outer surface of the plating on this portion may have both the contour of the original surface and a mat, etched, or frosted surface superimposed thereon. In other words, one portion' of the finished article has a plated surface substantially the same in character as the original surface, and another portion of the article has a plated surface possessing the characteristics of the original surface modified by the etching action of the plating solution. Thus, an engrailed article plated or finished by my process may have one portion with the surface of the engrailing bright, and another portion with the surface of the en- 35 grailing modified or frosted. Also, a polished article finished or plated by my process may have one portion of its surface bright, and another portion modified or frosted.

The contrast between the polished and modified portions of an article finished by my process is pronounced and I have found that in the manufacture of articles such as nameplates and the like that the design and description placed thereon was both ornamental and plainly eligible, and by employing my process such articles may be produced more economically and with a more pleasing and durable finish than by the processes known heretofore.

. f claim:

1. Process of producing a two-toned fin ish on a metal surface, comprising coating a portion of such surface with a substance that retards the action of elcctrodeposition on such portion but is gradually removed therel'rom during such action; immersing said coated surface in an electroplating solution 11a viug an ctch'ing action on said metal during said period of retarded deposition, subjecting both coated and uncoated portions of such surface to an electroplating operation in said bath; and continuing such operation until after such coating has become removed and until both the coated and uncoated portions are plated with an electrodeposit.

2. Process of producing a two-toned finish on a metal surface, comprising polishing said surface; coating a portion of such surface with a substance that retards the action of clectrodcposition on such portion but is gradually removed therefrom during such action; immersing said coated surface in an electroplating solution having an etching action on said metal during said period of retarded deposition, subjecting both coated and un' coated portions of such surface to an electroplating operation in said bath; and continuing such operation until after such coating 1 is become removed and until both the coated and uncoated portions are plated with an electrodol iosit.

3. Process of producing a two-toned finish on a metal surface, comprising coating a porticn of such surface with re-etching ink; immersing said coated surface in an electroplating solution having an etching action on said metal during said period of retarded deposition; subjecting both coated and uncoated portions of such surface to an electroplating operation in said bath; and continuing such operation until after such coating has become removed and until both the coated and uncoated portions are plated with an electrodeposit.

Process of producing a two-toned finish on a metal surface, comprising coating a portion of such surface with a substance that retards the action of electrodcposition on such portion but is gradually removed therefrom during such action; immersing said coated surface in a chromium plating bath having an etching action on said metal durinc said period of retarded deposition. subj cting both coated and uncoatcd portions of such surface to a chromium electroplating operation in said bath; and continuing such operation until after such coating has become removed and until both the coated and uncoated portions are plated with an electrodeposit.

5. Process of producing a two-toned finish on a polished metal surface, comprising coating a portion of said surface with re-etching ink; immersing said coated surface in a chromium plating bath having an etching action on said metal during said period of retarded deposition, subjecting said surface to a chromium electroplating operation in said bath; and continuing said operation until said surface is entirely plated with chromium.

6. Process of producing a nameplate, comprising polishing the surface of said nameplate; coating a portion of such polished surface with rc-etching ink; immersing said coated surface in an electroplating solution having an etching action on said metal during said period of retarded deposition, subjecting such partially coated surface to a chromium electroplating operation in said bath; and continuing said operation until the coated portion of such surface has become etched; until the coating has been removed from such surface; and until both the uneoated and formerly coated portions of such surface have become plated with chromium.

7. An electroplated article having substantially plane surface portions, an integral coating of a unitary metal thereon, said coat ing having portions of different character reproducing difi ercnt surface forms or charactor of the underlying metal, the thickness ofthe plated coating being different on said surface portions of differing character.

8. An electroplated article having substantially plane surface portions, an integral coating of a unitary metal thereon, said coat,- ing having portions of different character reproducing different forms or character of the underlying metal, one portion being an etched portion, the thickness of said plated coating being less on said etched portion than on the other.

9. An electroplated article having substantially plane surface portions, a coating of chromium thereon, said coating having portions of different character reproducing different surface forms or character of the underlying metal. the thickness of the plated coating being different on said surface portions of. differing character.

10. An electroplated article having substantially plane surface portions, a coating of chromium thereon, said coating having portions of different character reproducing different forms or character of the underlying metal, one portion being an etched portion, the thickness of said plated coating being less on said etched portion than on the other.

In testimony whereof, I affix my signature.

MARVIN J. UDY. 

